When the cotton is sufficiently pressed, it is spread on canvass, or railed wooden frames, and brought to the stove to be dried.
The stove consists of a chamber, of size proportionate to the work to be done in it, which is usually arched over with brick, and separate from the other build ings of the cotton factory, to prevent ac cidents by fire ; a flue of cast-iron runs through the middle of this chamber, a little above the floor, from a fire place, which opens outside. In some stoves, in verted pots, or metallic cylinders, are fixed at intervals along the flue, with which they communicate beneath ; wood en supports are placed round the sides of the stove, to sustain the frames on which the damp cotton is spread, which is left to remain here till it is thoroughly dry. As the stove may be constructed in vari ous manners, without any material dif ference in its performance taking place, it is probable that many other construc tions are used in different places ; but the one described is of a kind in very general use, and has no very obvious defect. It is probable a stream of heated air con veyed through the stove might be an im provement, tending to accelerate the dry ing process ; as it is very obvious, that when the air contained in the stove be comes loaded with moisture, it cannot absorb that of the cotton very readily. Double doors should also be added to stoves, with a small space between them ; and one door should always be shut again before the other was opened, to prevent the cooling of the stove, by the whole mass of heated air passing out at once, which must frequently take place in stoves with single doors.
Carding Engine for Jenny-spinning.
When the cotton is sufficiently dry, the next operation which it undergoes is that of carding. This is performed on an en gine which has now been brought to great perfection, of which, and of the manner in which it is used, the following is a description. The cotton is first spread on a feeding cloth, disposed in the same manner as that already described for the same purpose in the picking en gine; two small rollers, about an inch in diameter, take up the cotton between them, as it successively approaches them on the revolving cloth, and deliver it to a roller of from twelve to eighteen inches diameter, according to the size of the en gine, covered with cards of the fineness proper tor cotton : (cards for the opera tion of carding cotton or wool by hand, being used in most towns and villages, need not be described here, and will also be found under their proper head): from this roller the cotton passes to another of about the same size, from whence it is delivered to the great carding roller, which is from two to three feet in diame ter: about the upper half of this roller several small rollers are placed, of three or four inches diameter, between which and the great roller the cotton is carded, as well as between those of a larger size : another roller, of from twelve to eighteen inches diameter, takes the cotton from the large roller, and is again stripped of it by a kind of comb, with very short teeth of iron, which, moving up and down before the roller, strikes the cards in its descent in the direction of their teeth, by which the cotton is separated in a fine thin sheet, like a fleece, in which it passes between a smooth roller (which is mostly covered with fine paper), and a hollow semi-cylinder, that form it into oblong rolls, similar to those made by hand.card
ing, but much longer : on the surface of the smooth roller are small projections, parallel to the axis, at the distance of four or five inches from each other ; which, rolling the cotton between them and the semi-cylinder beneath, produce the effect described. These projections are formed in many engines by whipcord stretched tightly across in the proper places, before the paper is pasted on, which covers both them and the roller.
When the cotton is thus formed into rolls, it falls into a receptacle, whence it is taken to be slubbed.
It is to be understood, that the opera tion of carding performed by the several rollers described, is effected by each suc cessively moving faster than the one be hind it, and of course slower than the one before it, with the exception of the small rollers placed above the great roller, which move with an uniform velocity, and all much slower than the large roller. In some carding engines, formerly, a good deal of the motions were performed by toothed wheels and pinions, but of late years they are effected by bands, or straps, which produce a much more equable and steady movement. The large rollers are generally made by placing two or more wheels of cast iron on one axle, the cir cumferences of which wheels are cased with wood, which is attached to them by screws or rivets : the smaller rollers are formed in a similar manner on wooden disks ; but all are made hollow, to pre vent warping.